With the rapid development of mobile terminals such as mobile phones, there is an increasing number of personalized and modularized applications for various mobile terminals.
At present, mobile terminal users are not satisfied with the experience of the mobile terminal itself, and demand more requirements for the extended functions of the mobile terminals. In response, most manufacturers have tried to implement extended functions on the back cover of the mobile terminals but has yet to be realized, which brings great inconvenience to users using the mobile terminals.